Burner



NOV 17, 1942- J. G. BEHRENDT ETAL 2,302,287

BURNER Filed Feb. 12, 1940,

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Patented Nov. 17, 1942 BURNER John G. Behrendt and Lenie c. Ruthy, chicago, Ill., assgnors. to Ephraim Banning, Chicago,

lll., as trustee Application February 12, 1940, Serial No. 318,468

13 Claims.

This invention relates to a liquid 'fuel Vaporizing burner. It is a principal object of our invention to provide a liquid fuel burnerrwith a wide range of combustion stages, varying from avery loW fire to an extremely high fire, with automatic means for increasing the quantity of air introduced to combustion at each stage, thus proportioning the air intake to insure suflicient oxygen to completely burn the fue] at each of the various combustion stages, and thus maintain a high degree of combustion eiciency over the complete range. As a further object, the burner of our invention is provided with `means for rapidly varying the combustion rates whereby it may be quickly adjusted to any firing stage within itsv capacity.

It is also the object of this invention to provide a burner of the type described which is adaptable for any of -the very specialized and varied needs and uses which may arise. Finally, v it is our object to provide a burner of the above type, the parts of which are simple and economical of manufacture and assembly.

Other and further objects of this invention will be` apparent from the ensuing description wherein reference is made to the accompanying drawing which illustrates certain embodiments of our improved burner in the manner following:

Figure 1 is'a vertical sectional view of a heating cabinet equipped with the present burner in one of its forms;

Fig, 2 is a fragmentary section, taken on line 2--2 of Fig.1;

Fig. 3 is a vertical sectional view of a burner of modified form;

Fig. 4 is a fragmentary section of the lower portionv of a burner of stillI further modied form;

Fig.` 5 is an enlarged fragmentary sectional perspective view showing in detail the vaporizing ring which is a feature .of the burner-of Fig, 4;

and

f Fig. 6 is a vertical sectional view of a burner embodying another modified form of our invention.

In each`of the various forms of our burner, the construction includes a re pot A with circular walls I 0, having at its top an outwardly turned ange Il adapted to rest upon and be sustained by bracket arms l2 which are extended inwardly from the side walls M of a heating unit B here y shown as a cabinet or stove which comprises a bottomv I5, and a top I6.which is fitted upon the upper end of the cabinet, all as indicated clearly are formed for admitting air to the interior of the cabinet. g

The re pot, which is adapted to receive its fuel from a supply source (not shown) Athrough a pipe |8may comprise three superposed ring chambers a, b and c, the lowermost chamber a being smaller in diameter than those above. The bottom of this lowermost chamber, which serves also as the base of the re pot, is raised centrally as at 20, so as to form adjacent the peripheral 4wa'll of the burner an annular trough in Fig. 1.* Through the bottom l5, apertures n 2| to receive liquid fuel. At a point about midway of the height of the lowermost chamber, a single circumferential row of spaced ports 22 is formed through the peripheral wall of the burner.

The re pot is also formed with an inward crimp 23 defining a circumferential ledge 24, below which, at the innermost point of the crimp, is formed a plurality of closely spaced perforations 25 through which air may enter into the burner at an elevation where the minimum diameter obtains. The crimp partially separates the lowermost from the middle firing chamber b which is of increased diameter, and which may be provided with upper and lower circumferential rows `of ports 26 and 2l, respectively. An inwardly extending bead 28 serves as a support for anannular bale`p1ate 29 which partially separates tne middle from the uppermost firing chamber c.

I'his top .chamber is provided near its upper edge .with a single row of closely spaced ports 30 of increased diameter to admit a relatively large volume of air into the burner at this point. An annular plate 3|, which is mounted upon the top of the re pot, provides an upper baffle and 'axial outlet for the ames and products of combustion. The opening in the plate is somewhat greater in diameter than is the opening in the lower baille plate 29, for a reason that will be later pointed out. The top baile plate may be centered as by lugs 32 which engage with the burner Wallsi.

In Fig. 3 we show a generally similar burner construction, but'diiering in the respect that the bottom of the nre pot which rises upwardly toward its center is formed with an axial tubular `air injector 35 whereon may be supported a steel #of the injector to assist in directing the gaseous currents radially. The injector is provided with a row of circumferentially arranged spaced air ports 31 at a point where air may be effectively supplied to support combustion at the initial rf ing stage. A threaded rod 38 depending from the cap adjustably supports a disk 39 forming an air control valve adapted to be raised or lowered by a turning wing nut 40 for varying the quantity of air admitted to the injector. ,The top of the cap, as shown, is slightly below the row of ports 22 in the walls of the re pot.

In Fig. 4` we have'shown an air injector 45 modified to the extent that its tubular walls are closed by a top wall 46, there being a circumferential row of spaced ports 41 located at a point where air may be effectively supplied to support combustion at th e initial ring stages.

Figs. 4 and 5 illustrate the addition of a vaporizing ring 50. This ring, which is of substantially less diameter than the crimp 23, has a relatively greater vertical dimension, thus facilitating its support and centering by certain arms 5| which extend radially therefrom close to the circular walls of the re pot in a position to rest upon the ledge 24. The vaporizing ring is provided with a circumferential row of spaced ports 52 of larger diameter than the opposite ports 25 in the adjacent crimp 23. i

In Fig. Gis shown a further modified re pot wherein the' general structure is the same as those already described except for the absence of a crimp to separate the lowermostfrom the middle ring chambers, the latter being also stepped back by the provision of a second ledge 55 at a point substantially midway of its height. Above `the stepped middle chamber b, the walls of the re pot rise vertically to dene the uppermost chamber c. It will thus be noted that the middle chamber has two diameters, the larger being the same as the topmost chamber but the smaller being greater than that of the lowermost chamber. This form of burner (as indeed may any of the others herein described) may utilize a vaporizing ring 5 0, the ports 25 cooperating therewith in the manner which will presently be explained, also an axial air injectorV and annular baille rings, all as previously disclosedl in connection with the remaining figures of the drawing.

When operated, fuel is supplied through the supply pipe I8, combustion being initiated at the bottom of the lower firing compartment a, 'close to the peripheralwalls of the burner.- As heat is generated, air is drawn in through the various ports to support combustion'within the re pot. In its rst stage, combustion will be conned to the bottom ring compartment, but with increase of temperature vaporization takes place to an increasing extent, producing in later stages an ever vertically higher zone of mist at the bottom of the fire pot, with the result that the Visible combustion rises to a point well up in the lowermost compartment.

The inwardly extending crimp 23 serves as a constriction to slow the upward progress of the combustible gases, the ports 25 therein providing (l) the dominant oxygen supply for the burner in the low combustion stage, and (2) the primary oxygen supply when vaporization -is proceeding at a faster rate in the higher combustion stages. As the gases move upwardly into the middle ring chamber of v relatively greater diameter they are free to expand laterally, so that their upward travel becomes outward as well upon entering the middle chamber. The eiect of this is to delay the upward movement of the gases, thereby providing greater opportunity for air entering the fire pot through the lines of ports 25, 21 and 26, to produce a completely combustible mixture. The comminglmg of the air and vaporized fuel is also promoted by (l) confining the liquid fuel to an annular area adjacent the peripheral walls 'of the burner, thereby causing the combustion, ininitially at least, to remain close to such walls where the entering air first meets with the rising gases to aord combustible support thereto; (2) optionally supplementing the supply and admixture of air through the use of a central injector adapted to deliver the air radially from within the column of gases which rises annularly from the base of the burner; (3) optionally utilizing a deiiecting head in the nature of a cap which is applied over the injector, the aring periphery of this headradiating heat to the base to cause immediate contact of oxygen with heavy ends of the fuel oil, and the upper face of this head impelling combustion and creating a secondary ignition in the medium ring stages; and (4) by delivering further quantities of air to support combustion at the points where travel of the gases is slowed down, if a constricting crimp be em'- ployed, and where lateral expansion of the gases starts upon entering the middle firing chamber and elsewhere 'therein as the combustion gases proceed on upwardly.

Continuing on upwardly, movement of the gases is retarded by the bafe plate 29, through the central opening of which they pass into the topmost chamber c and thence out through the central opening, somewhat larger, of the top baille plate 3|. It is in this topmost chamber that the maximum supply of air is admitted to support combustion. This may be termed a secondary supply, inasmuch as it is admitted at a point remote from the source of combustion. The eiect of this final and plentiful'admixture of oxygen is to produce a clean flame during high fire operation.

It will be noted that the passage of the gaseous mixture is somewhat retarded by the baffle plate 29, so that the combustible gases are halted in the middle chamber where they are free to ex-.

pand laterally and absorb fresh quantities of oxygen to support the combustion. Again, upon passing this baille, the gases are detained by the top baffle plate 3| within the topmost ring chamber where, in a relatively s mall space, a large amount of air commingles with the gaseous fuel to promote complete combustion thereof as the flames emerge through the top of the burner, all without objectionable pulsations or vibrations.

With each or any of the various forms of our present burner, a vaporizing ring 50, as best shown in Fig. 5, may be used to advantage.

Without such a ring, the air entering through the ports 25 tends tobe rifled in from all sides.. This results in an opposing action causing iiring' hindrance in the intermediate combustion stage. The air so rushing in exerts a cooling effect which tends to retard combustion at or near the walls of the burner.

'I'he vaporizing ring counteracts these tendencies. This is due in part to the size of the air ports in the vaporizing ring which are larger than those opposite in the crimp of the re pot.

' The air entering the burner at this constriction point is halted somewhat upon striking the ring, then continues on through the openings therein, its force considerably diminished and otherwise conditioned for intimate admixture with the heated upwardly rising combustible gases.

In operation, this vaporizing ring becomes quite hot and, in consequence, the vapors passing upwardly, whether inside or outside of the aaoaasv ring, are heated to enhance combustibility of the fuel. This promotes the combustion process ad.

jacent the walls of the burner, tending to prevent deposit thereon of unconsumed carbon particles. The result of this improved combustion is an intense blue fiame which fills the upper two charnbers of the burner.

A characteristic feature is the comparatively restricted area of the oil well in the base, permitting the maintenance of low combustion rates, when desired, and the provision in the upper firing chambers of relatively greater areas into which the rising gases may expand, thereby conducing to an upward and outward travel of the gases as they leave the lowermost firing chamber. This outward movement of the gases is accordingly delayed suciently to allow an intimate admixture with the rich fuel vapor of fresh quantities of air introduced into the upper firing chambers in the manner hereinbefore described at length. A

Certain of the'features of our invention, particularly those which are illustrated in Fig, 3 of the drawing, were first disclosed and claimed in our earlier application for patent filed September 10, 1937, Serial No. 163,168, of which this case is a continuation in part.

We claim:

l. In a burner, a fire pot having a bottom, cylindrical side walls and an annular top, the side walls of the pot being formed intermediately of their ends with \an inwardly extending crimp wherein is a series of air portsdisposed at its innermost point, the crimp dividing the fire pot into upper and lower firing chambers, the lower of which is of lesser cross-section area, there beingports through the walls for admitting air into the pot below and above the crimp, and means for feeding liquid fuel to the fire pot at a point adjacent its base.

2. In a burner, a fire pot having a bottom, ,cy-

lindrical side walls and an annular top,the bottom being raised centrally to form a circular fuel trough, the side walls of the fire pot being formed intermediately of their ends with an inwardly extending crimp wherein is a series of air ports disposed at its innermost point, the

crimp dividing the fire pot into upper and lower firing chambers the lower of which is of lesser cross-sectional area, an annular baie positioned in the upper chamber defining therewithin two superposed chambers, there being ports through the walls for admitting air into the pot at points within each of the chambers therein, and means vfor feeding liquid fuel to the re pot at a point adjacent its base.

3. In a burner, a 'fire pot having a bottom and cylindrical side walls, a top therefor having a central aperture, a tubular injector rising from the bottom and terminating in an outwardly flaring metal cap extending horizontally beyond the walls of the injector, the cylindrical side walls of the pot having intermediately of their ends an inwardly extending crimp provided with a series of air ports at its innermost contour and dividing the space within the re pot into upper and lower cylindrical firing chambers, a series of air ports in the tubular injector below the metal cap, aseries of air ports in the cylindrical walls of the pot below the crimp, air portsinthev the bottom yand terminating in an outwardly flaring metal cap extending horizontallybeyond the walls of the injector, the cylindrical. side walls of the pot having intermediately of theirl ends an inwardly extending crimp provided with a series of air ports at its innermost contour and dividing the space within the re pot into upper and lower cylindrical' ring chambers, a series of air ports in the tubular injector below the metal cap, two vertically spaced series of air ports in the cylindrical walls of the pot below` the crimp, the series of air ports in the injector being located yvertically between said two series ofl air ports in the side walls of the pot, air ports in the side walls above the crimp, and means forl feeding liquid fuel to the fire pot.

5. In a burner, a fire pot having a bottom and cylindrical side walls, a top therefor having a central aperture, the cylindrical side walls of- `the pot having intermediately of their ends an spaced apart at unequal distancesto define two chambers, one above the other, the upper chamber' having the greater cross-sectional area, means for feeding a volatile liquid fuel to the fire pot adjacent its base, and means for admitting air into the fire pot at points within each of the chambers therein, one of such'points. being near the top of the` lower chamber whereby to produce an admixture of fresh air with the fuel whilein a Volatile state, immediately prior to its further rise and lateral expansion within the ,enlarged upper chamber.

7. In-a burner, a fire pot having a bottom,

side walls and a top with a central aperture, the

' bottom being raised centrally to form an annular fuel trough, a tubular injector rising from the bottom and terminating in a closed upper end, the walls of the pot being inwardly crimped at a point intermediate their ends to dene upper and lower firing chambers, there being a series of ports in the tubular injector so placed as to direct air issuing therethrough in a radial direc,- tion, and other series of ports through the pot walls vertically spaced for positioning one above the other and above the series of ports in the injector', another at the innermost contour of the crimp, and another in the'upper firing chamber, and means for feeding fuel to the re pot adjacent its base.

8. In a burner, a flre pot having an offset definingupper and-lower chambers with a ledge therebetween, the pot being provided through its Walls with ports for admitting air into the lower chamber at a point just below the ledge, a'vaporlizing ring adapted for suspension within the fire pot at a point oppositethe-ports just below the cylindrical pot walls above the crimp, and means for feeding liquid fuel to the fire' pot.

4. In a burner, a fire pot having a bottom and cylindrical side walls, a top therefor having a central aperture, a tubular injector vrising from izing ring having its greatest cross-sectional dimension vertically disposed to extend above and below the ports opposite thereto .and being formed therethrough with a plurality `of openings having an aggregate area greater than that afforded by the opposite openings in the fire pot, whereby air entering into the flre pot at` that point is caused to diffuse upon striking the vaporizing ring and, after halting, to proceed with diminished force inwardly thereof through the openings therein.

9. In a burner, a iire pot having a bottom, sides and a top with a central aperture, the bottom being raised centrally to provide an annular fuel trough adjacent the pot sides, the re pot comprising a plurality of superposed chambers with the lowermost having the smallest crosssectional area, an annular baiiie plate positioned within the uppermost chamber at a point intermediately of its upper and lower ends and so related to the apertured top as to define therewith a relatively restricted space, the bale plate being formed with a central aperture of less diameter than the aperture in the top, and means for admitting air into the several chambers of the re pot, the air admitted into the restricted space above the baiiie plate being in relatively large volume whereby to produce, with the combustible gases passing therethrough, an admixture of air in plentiful volume to promote complete combustion of the gases without pulsations.

10. In a burner,` a fire pot having a bottom, sides and a top with a central aperture, together with means for supplying fuel to the pot adjacent its bottom, the re pot comprising aA pair of superposed chambers with an intervening inwardly extending crimp, an annular baille plate positioned within the upper chamber at a point intermediatelyvof its upper and lower ends and in spaced relation to the crimp and so related to the apertured top as to define therewith a relatively restricted space, the baille plate being formed with a central aperture of less diameter than the aperture in the top, and means for admitting air into the two chambers of the fire pot and into the space therebetween in theplane of the crimp, the air admitted into the restricted space above the baille plate being in relatively large volume whereby to produce, with the combustible gases vpassing therethrough, an admixture of air in plentiful volume to promote complete combustion of the gases Without pulsations.

11. In a burner, a fire pot having a bottom, sides and an apertured top, the re pot comprising a plurality of superposed chambers with the lowermost having the smallest cross-sectional area, an annular baiile plate positioned within the uppermost chamber at a point intermediately of its upper and lower ends and so related to the apertured top as to define therewith a relatively restricted space, the baiile plate being formed with a central aperture of less diameter than the aperture in the top, and means for admitting air into the several chambers of the re pot, the air admitted into the restricted space above the baille plate being in relatively large volume whereby to produce, with the combustible gases passing therethrough, an admixture of air in enhanced volume to promote complete pulsationless combustion of the gases.

12. In a burner, a re pot having a bottom, sides and an apertured top, the re pot comprising a plurality of superposed lchambers, an annular baille plate positioned within the upper chamber at a point intermediately of its upper and lower ends and so related to the apertured top as to define therewith a relatively restricted space, and means for admitting air into the several chambers of the re pot, the air admitted into the restricted space above the baiile plate being in relatively large volume whereby to produce, with the combustible gases passing therethrough, an admixture of air in enhanced volume to promote complete pulsationless combustion of the gases. y

13. In a burner, a lire pot provided through its walls, intermediately of its ends, with a circular row of ports for admitting air thereinto, a vaporizing ring within the re pot and located at a point opposite the ports and in spaced relation thereto, the vaporizing ring having its greatest cross-sectional dimension vertically disposed to extend above and below the ports opposite thereto and being formed therethrough with a plurality of openings having an aggregate area greater than that aiorded by the opposite openings in the fire pot, whereby air entering into the flrepot 'at that point is caused to diffuse upon striking vthe vaporizing ring and, after halting, to proceed with diminished force inwardly thereof through the openings therein, and means for supporting the vaporizing ring in place within the re pot.

JOHN G. BEHRENDT. LOUIS C. RUTHY. 

